First and novel oxidation of d-fructose by potassium iodate using [IrCl3(H2O)2OH]− complex as a homogeneous catalyst in alkaline medium

The kinetics of Ir(III)-catalyzed oxidation of d-fructose by potassium iodate was studied in an aqueous alkaline medium at 40 °C. The experimental result shows a first order dependence on iodate and [OH−] at their low concentrations, but tending towards zeroth order at their higher concentrations. Zero order kinetics with respect to [d-fructose] was observed throughout its variation. The linear dependence of the reaction rate at lower [Ir(III)] chloride tends towards zero order at its higher concentrations. Variation in [Cl−] and ionic strength of the medium did not bring about any significant change on the rate of reaction. The decrease in the rate of reaction with increase in the dielectric constant of the medium was observed in the oxidation of d-fructose. Kinetic and equivalence studies together with product analysis, observed effect of dielectric constant of the medium on the rate of reaction, activation parameters and multiple regression analysis furnished a basis for the formation of a common reaction mechanism for the iridium(III)-catalyzed oxidation of d-fructose by iodate in the alkaline medium.

The following general scheme is proposed for the first and novel oxidation of D-fructose by potassium iodate using [IrCl3(H2O)2OH]− complex as a homogeneous catalyst in alkaline medium to explain the observed experimental results:Figure optionsDownload as PowerPoint slide